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Dwelling types for BASIX 



The Building Sustainability Index (BASIX) aims to deliver equitable, effective water and

greenhouse gas reductions across the state. BASIX is one of the strongest sustainable

planning measures to be undertaken in Australia.

BASIX and the planning system

An integrated part of the planning system, BASIX is implemented under the Environmental Planning and Assessment Act. BASIX applies to all residential dwelling types and is part of the development application process in NSW.

BASIX assessment

BASIX is assessed online using the BASIX assessment tool. The tool checks elements of a proposed design against sustainability targets.


BASIX reduces water and energy consumption in homes across NSW. These environmental outcomes also provide a long term financial saving for the homeowner – and a valuable contribution to the sustainable future of our communities. 

That is why you need to use our professional service. As we do BASIX assessments, BASIX certificates day in and day out, we have all the required experience and we will ensure that you will not be out of pocket with unnecessary provisions and technical solutions.

BASIX New Targets

As BASIX new targets have been rolled out since July the 1st 2017, the nature of our work has changes quite a lot, as demands have increase significantly.

The new BASIX targets mainly affect the thermal comfort section as BASIX heating and cooling loads parameters have been altered significantly.


What this means. Pre-July 1st 2017, in climate zone 56 for example (coastal Sydney) heating load limits on average were 51 MJ/m2.annum and cooling load limits were 45 MJ/m2.annum.


Currently, under the new BASIX thermal comfort targets, in the same climate zone, heating load limits on average are 40 MJ/m2.annum and cooling load limits were 26 MJ/m2.annum.

What does this mean for the new developments?

  • Basically, the building must be able to perform better both in summer and winter in order to meet minimum requirements

  • Window areas may need to be reduced in comparison the old standards

  • Window specifications may need to be increased and sometimes significantly to meet new standards

  • Higher levels of insulation may need to be added

  • Higher thermal mass can be considered

  • Higher build costs all up

  • Better homes to live in

  • Much lower running cost of the buildings

  • More environmentally friendly buildings

What is currently a hindrance, and what we as assessors have asked the regulators, is to allow us to model ceiling fans as they play a very important role in keeping the dwelling cool in summer. They also allow for lower window specifications overall, hence keeping costs to lower levels, however in NSW, currently we do not have this option available to us.

If you are about to start designing your new project, look for;

  1. Orientation and sun exposure are two very important factors, so where possible use them ti benefit your outcomes

  2. Build as close to the square shape as possible. Long and narrow buildings tend to suffer either in summer or winter and in some cases throughout the year

  3. Limit as much as possible glazing areas

  4. Utilize openable windows rather than fixed where possible

  5. Keep an open mind for colour tone scheme as they play an important role too

We hope that this short article has been useful and if you like ti find out more, you can contact us as



BASIX - New Homes & Apartment Buildings - NSW


All new houses and apartment buildings are required to have a BASIX certificate completed as part of development applications. The BASIX tool has three segments;


Water, Thermal Comfort and Energy.

Water efficiency - nominally a reduction of water consumption by a minimum of 40% compared to a standard house (house without any water saving measures) for new houses/townhouses and by 30% compared to a standard apartment for apartments. The water usage reduction for

apartments, sometimes is also at 40% depending on suburb, size of development, etc. 


Water efficiency is primarily achieved via the use of rated water appliances (shower heads, taps, cisterns), the utilization of rainwater tanks for garden watering usage and sometimes for laundry,

and toilets as well as pools whenever applicable.

Thermal comfort - NatHERS is a national scheme although not compulsory to all states, however is compulsory in NSW. It is a scheme where dwellings are rated according to their thermal performance for summer and winter. That is achieved via the simulation of the proposed

dwelling by specialty software packages such as AccuRate, Firstrate and Bers. The way this is done is the whole geometry of the subject building, including neighboring buildings for shading, location, orientation and building constructions are inputted. All of the above are calculated thus predicting cooling and heating loads. BASIX has benchmarks for these loads mainly dependent on location and building type, however other secondary parameters are taken into consideration.

Once the software produces the predicted loads, they then are compared to BASIX benchmarks. If loads are higher than allowed, mainly construction specifications (walls types, insulation levels, window types, colours etc) are altered / optimized in order to make the dwelling comply.

Single dwellings can also be assessed via the use of the simple method, a method that can be assessed by anyone however be careful on the commitments as they will be checked by the certifier and non-compliance, will need to be addressed.

Energy efficiency - similarly to the water efficiency section, electric appliances such as water heaters, a/c, lights, and other, sometimes including solar photo-voltaic systems are specified in order to achieve 30% - 40% energy usage reduction compared to a standard dwelling. Thermal comfort section can affect the energy efficiency performance as a well, since a well performing dwelling requires little on no a/c usage, thus contributing positively to this section.

All of the above is combined in one document, the so called BASIX certificate and is used as a specification sheet for architects and builders for the building phase and as a checklist for building certifiers at the completion stage of the project in order for the Occupation Certificate to be issued.

All information outlined in the BASIX certificate and in the HSTAR universal certificate (thermal comfort section) must be reflected 100% in the building.

In other states, BASIX is not applicable and reference solely to the BCA is taken into account, however for thermal the comfort, NatHERS is the only scheme available


To address the thermal comfort section of BASIX, AENEC provide their clients a thermal simulation by using the AccuRate software and is able to provide you with complete and accurate design advice.


AENEC also specialises in multi-unit BASIX certifications for apartment buildings and having assessed many multi-unit projects we have an extensive knowledge of the process.


For our multi-unit fee schedule, please contact us.
Downloads and Samples

What is a BASIX® Certificate?

What is BASIX® Certificate? The BASIX® Certificate or BASIX® (The Building Sustainability Index), is a NSW Government planning requirement that affects anyone submitting a Building Application in NSW for a new house, alteration, addition, villa, townhouse, units, plus a swimming pool or outdoor spa.

Operating as a web-based tool, BASIX® is used to assess each new application against specific energy and water reduction targets. BASIX® means every new home, alteration or extension built in NSW will be more comfortable to live in and cost less to run, and each swimming pool or outdoor spa will meet specific BASIX® requirements for water and energy consumption.

The BASIX® tool is used to calculate the house or unit’s energy and water scores based on a range of data, including size, location, design features and fixtures.

Once the necessary commitments have been met, a BASIX® Certificate is generated which lists the schedule of commitments for your application.  All the commitments listed on the BASIX® Certificate must be indicated on the architectural plans.

Independent research shows that owners of new homes which comply with BASIX® can slash household water and power bills by up to $600 a year on average.

Overall, the BASIX® Certificate is a NSW Government initiative that ensures new homes are designed and built to use less potable water and produce fewer greenhouse gas emissions, with the purpose of providing a sustainable future.

For more information on BASIX® go to the NSW Government website.

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"BASIX® is a registered trade mark of NSW Department of Planning and is reproduced here under licence.  
The services provided by Peter Waller and BASIX Certificate Centre are not in any way endorsed by or 
otherwise associated with the NSW Department of Planning."

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